Trying to rewrite a programm using recursion.

Question

Hello sololearners and sologurus!
I want to rewrite a programm using recursion and I can't really wrap my mind about this concept and how should I use it in this case.
I know that I must declare a function and this function should call itself.
Any help is welcomed.
I have this programm:
// frequency of a nr in a given array

#include <iostream>
using namespace std;
int main(){
int a, arr[5], counter=0, i;
cout<<"Enter a:" <<endl;
cin>>a;
cout<<"Enter elements of the array: "<<endl;
for(i=0;i<5;i++){

cin>>arr[i];
}
for(i=0;i<5;i++){
if(a==arr[i])
counter++;

}
cout<<"We have nr "<<a<<": "<<counter<<" time(s) in the array."<<endl;
return 0;

}

And I want to rewrite it using recursion.

Answer 1

#include <iostream>
using namespace std;

int f(int val, int i = 1) {
int a;
cin >> a;
return (a == val) + ( i < 5? f(val, i+1): 0);
}

int main() {
int val;
cout << "Enter value: ";
cin >> val;
cout << "Enter 5 elements of the array: " << endl;
int count = f(val);
cout << "We have number " << val << ": " << count << " time(s) in the array." << endl;
}

Answer 2

#include <iostream>
using namespace std;

int RecursiveCount(int array[], int value, int index, int size)
{
if(index == size-1)
return array[index] == value ? 1 : 0;

if(array[index] == value)
return 1 + RecursiveCount(array,value,index+1,size);
else
return 0 + RecursiveCount(array,value,index+1,size);
}

int main() {

int a[10], value, sizeOfArray;

cout<<"Enter desired value";
cin>>value;
cout<<endl<<"Enter the size of array(between 1 and 10)";
cin>>sizeOfArray;
if(sizeOfArray < 1 || sizeOfArray > 10)
{
cout<<endl<<"Wrong size of array!" ;
return -1;
}
cout<<endl<<"Enter the elements of the array:";
for(int i=0; i<sizeOfArray; i++)
cin>>a[i];

int count = RecursiveCount(a,value,0,sizeOfArray);

cout<<endl<<endl<<"We have a number of "<<count<<" appearances of value "<< value<<" in the given array"<<endl;

return 0;
}

I made the program run for any array with a size between 1 and 10. Using the recursive function, I go through all numbers from array. The stop condition consists in arriving at the last nr from array. if the last nr from array is equal with my desired value, i return 1, else i return 0. For the rest of array, I return 0 + f(nextElement) if nr[i]!= value and 1 + f(nextElement) if nr[i]==value.

I hope the code is written clearly enough and easy to understand :)